Food consumption of garden birds (1 Viewer)

[johnraven]

Does anyone know how many calories or quantity of seed different types of common (UK) birds consume each day? E.g. how many grams of bird seed does a house sparrow need? Or a wood pigeon? I understand this varies greatly according to temp/activity, but I'm just after a guesstimate.

The reason I ask is that I wish to estimate how many birds my current seed output of c.500g per day supports? The food is consumed predominantly by House Sparrows, Wood Pigeons, Collared Doves and Blackbirds.

A quick google search was unfruitful, surprisingly.

 

[johnraven]

I found an answer to my own question, in "Kleiber's Law".
Apparently daily calorie requirement equals K x B ^ 0.75 x F, where
K is the animal co-efficient (129 for passerines, 78 for non-passerines);
B is the body mass, in Kg; and
F is Basal factor, which is 2 for adult bird and 4 for young growing bird
( ^ 0.75 means to the power of 0.75).

As mixed seed has about 420 calories per 100g, the seed (or equivalent) requirements are (for adult bird):

House Sparrow: 4.4g
Starling: 8.8g
Blackbird: 11g
Wood Pigeon: 21g

I reckon my garden supports about 45 House Sparrows, 11 Starlings and a few blackbirds and doves.